The Church of St. John the Baptist is a domed cruciform church, built of undressed stone. It is one of the best preserved churches in Nesebar. It is 12 meters long and 10 meters wide. The structure of the church consists of two cylindrical vaults which intersect in the center of the composition. The masonry is crushed stone and pebbles and the facades were probably smoothly plastered. It was built in the 11th century. The altar space consists of three semi-circular apses. Four massive pillars support the dome and form the cross. Inside the church the walls are smooth and unbroken. The exterior is simple without decorative niches and ceramic plaques, typical of the ornamental style. Bricks were used as a decorative element over the entrance, in the jagged cornices and around the windows.
Some frescoes in the church have been preserved dating from later periods. The faded portraits of the donor and his contemporaries on the southern wall and the fragments beneath the dome date from the 14th century and the others are from the 16th and 17th centuries.
The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.